New polymers and detergent compositions containing them

ABSTRACT

New copolymers of acrylic and methyl acrylic acid (I) with acrylic and methacrylic acid - ethylene oxide condensates (II). The components have formulas: I. CH2 C(R)COOM II. CH2 C(R)COO(C2H4O)nH wherein R is H or CH3; M is H, alkali metal, ammonium or amine; and n is at least one. The preferred ratio of (I) to (II) is about 2:1 and n is preferably from 20 to 100. These compounds are mixed with surface-active agents to form built detergents. They are most effective as whiteness maintenance agents when added to a detergent composition at a 0.1 to 5 percent level by weight of the final product.

United States Patent [191 Hardy et al.

[ 1 March 6, 1973 NEW POLYMERS AND DETERGENT COMPOSITIONS CONTAININGTHEM Inventors: Frederick Edward H ardy, Newcastle-upon-Tyne, England;Peter Robson, Brussels, Belgium; Peter Roscoe Hartley Speakman, Durham,England The Procter & Gamble Company, Cincinnati, Ohio Filed: Jan. 25,1971 Appl. No.: 109,657

Assignee:

US. Cl ..260/86.l R, 252/112, 252/523,

Int. Cl. ..C08f 15/14, C08f 15/16 Field of Search ..260/86.l R, 86.1 N

References Cited UNITED STATES PATENTS 3/1967 Bearden ..260/86.1 R

3,370,050 2/ 1968 Seiner ..260/86.l R 3,501,432 3/1970 Wright et a1.....260/86.1 R 2,244,703 6/1941 Hubbuch ..260/86.1 R

Primary Examiner-Harry Wong, Jr. Attorney-Julius P. Filcik and RichardC. Witte [5 7] ABSTRACT These compounds are mixed with surface-activeagents to form built detergents. They are most effective as whitenessmaintenance agents when added to a detergent composition at a 0.1 to 5percent level by weight of the final product.

8 Claims, No Drawings NEW POLYMERS AND DETERGENT COMPOSITIONS CONTAININGTHEM BACKGROUND OF THE INVENTION:

The invention relates to new copolymers having useful properties,especially as components of washing compositions. Thus they may beeffective for improving whiteness maintenance, as lime soap dispersantsand as detergency builders.

While the primary function of a detergent composition is to remove soilfrom articles being washed, an important secondary function is toprevent the soil removed from dirtier articles or parts of articles frombeing redeposited upon cleaner articles or parts of articles which arebeing treated in the same wash liquor. This activity is known aswhiteness maintenance and is measured, in principle, by determining theloss of whiteness of clean white fabrics (or surfaces) when washed instandard conditions together with soiled articles, or in a detergentliquor containing soil.

Lime soap dispersants are substances incorporated in soap products, assoap-containing wash liquors which present the formation or thedeposition of insoluble soaps formed by reaction of soluble soaps withthe constituents of hard water.

Builders are agents, usually alkaline and/or having calcium sequesteringproperties, which enhance the cleaning power of organic detergents.

The present copolymers are particularly effective as whitenessmaintenance improvers when employed in dilute washing liquors containingphosphatic builder salts including pyro-and/or ortho-phosphates, that isin liquors wherein there is not enough sequestrant builder salt presentto sequester all the calcium ions strongly enough to prevent calciumpyroor ortho-phosphates being precipitated. These calcium ions areusually derived primarily from the water hardness, but may also bederived from the soiled articles being washed. Thus, as a typicalinstance, a conventional tripolyphosphate-built heavy duty granulardetergent, prepared by spray drying, normally contains a proportion ofpyroand ortho-phosphates as a result of partial reversion (hydrolysis)of the tripolyphosphate during mixing and spray drying. If, as is notuncommon, such a composition is used in hard water at a concentrationsuch that there is insufficient unreverted tripolyphosphate present tosequester all the calcium etc. in the hard water, the whitenessmaintenance is likely to be poor. The copolymers of the invention areparticularly valuable in overcoming this fault. While the invention doesnot depend on any theory of the mechanism whereby these agents act, itappears that the insoluble calcium pyroor ortho-phosphates encourage oraggravate the redeposition of soil, and that the copolymers of theinvention diminish, or affect in some other beneficial way, the effectof said calcium phosphates.

BRIEF DESCRIPTION OF THE INVENTION The new polymers are copolymers ofacrylic or methacrylic acid or their salts having the formula CH=C(R)COO M with one or more acrylic or methacrylic derivatives havingthe general formula:

wherein R is H or CH M is hydrogen or a cation such that the copolymersare water soluble, and n is at least one. Preferred copolymers are thosederived from acrylic acid and methacrylic derivatives, i.e., derivativeswhere R is CH;,. Preferably M represents an alkali metal (especiallysodium), ammonium or an amine.

The invention also provides detergent compositions comprising an organicdetergent and a copolymer as defined above, and, especially suchdetergent compositions also comprising a builder salt includingpyroand/or ortho-phosphates.

The invention also provides a laundering process in which fabrics arewashed in a solution of a detergent composition according to theinvention, especially a process in which there is insufficientsequestering agent present in the wash liquor to sequester all calciumions present in the wash liquor.

DETAILED DESCRIPTION OF THE INVENTION The copolymers of the inventionmay be prepared in any effective way. For instance, a polyethyleneglycol of the desired mean molecular weight (i.e. desired average numberof polymerized ethylene oxide residues) may be reacted with methacrylicor acrylic acid anhydrides in the presence of a catalyst. The resultingester may be copolymerized with methacrylic or acrylic acid by methodsknown in the art for making acrylic-type polymers. It may not benecessary, though it is of course permissible, to separate thecopolymers in the reaction product from impurities, such as unreactedmonomers, present with them when the material is to be used in detergentcompositions. In the acrylic or methacrylic derivative used in thecopolymers, n is one or more, generally up to about 150. As agentsenhancing whiteness maintenance, the preferred copolymers have n fromabout 20 to 100, especially at the upper end of this range. As soap scumdispersants, the preferred compounds have n from about 5 to 10,especially about 6. The preferred ranges of values of n stated refer tothe mean values when, as is usual, compounds with a range of n valuesare present together.

In preparing the copolymers in weight ratio of acrylic or methacrylicacid to the acrylic or methacrylic derivative is preferably from about1:1 to about 5:1 and especially about 2:1.

The degree of copolymerization is usually preferably such as to providecopolymers having molecular weight of the order of 30,000 to 200,000,but reaction mixtures containing copolymers and some unpolymerized orlittle polymerized materials and having an apparent molecular weight aslow as about 3,000 have proved effective.

In detergent compositions, the proportions of the copolymers which canusefully be incorporated varies widely. Thus, especially if they areintended as detergency builders, considerable proportions of thecopolymers may be used, for instance up to 50 percent or more by weightof the composition. When they are intended as lime scum dispersants orwhiteness maintenance improvers relatively small proportions are usuallysufficient, for instance from about 0.1 to about 5 percent, andespecially about 1 percent. Larger proportions are, however, effectivefor these purposes also and the optimum level will depend upon economicand like considerations.

Apart from their content of the copolymers of the invention, thedetergent composition may be conventional, and in any physical form.Thus, they may con tain as organic detergent soap or other anionicdetergent, or nonionic, semipolar, zwitterionic or cationic detergents,and the usual builder salts such as ortho, pyro or tripolyphosphates,carbonates, silicates, sulfates, borates and the like, or organicsequestrant builder salts such as nitrilotriacetates, ethylene diaminetetra-acetate, ethane- 1 -hydroxy-l 1 -diphosphonates, and the like.These may be present as the sodium, potassium or ammonium or aminesalts, more usually the sodium salts. Also present may be bleachingagents such as peroxygen or chlorine bleaches, and the usual minorcomponents of detergent compositions such as coloring matter, perfumes,enzymes, other soil suspending agents, tarnish inhibitors, sudsenhancing or depressing agents, preservatives, germicides, stabilizersor activators for the bleaching agents or enzymes, and the like.

The invention is illustrated by the following Examples:

EXAMPLE I Preparation of Polyoxyethylene Monomethacrylate Forty g. ofpolyoxyethylene glycol, of molecular weight 4,000, in 40 ml. of pyridinewere treated with 1.5 g. methacrylic acid and 50 mg. of hydroquinone.The solution was kept at 50-60 C. for 3 days and then poured. into 500ml. of ether. The precipitated monoester, 40 g., was collected andwashed with ether. This was the compound corresponding to the formula CH=C(Cl-l )COO (C H O),,H wherein the mean value ofn was about 90.

PREPARATION OF COPOLYMER Glycol EXAMPLE II A detergent composition A wasprepared consisting essentially of:

17.5% Sodium dodecylbenzene sulfonate 46.2% Sodium tripolyphosphatecontaining about 20% by weight thereof of pyrophosphate 7.3% Sodiumsilicate monethanolamide 1.8% Coconut rnonoethanolamine 1.0% Sodiumcarboxymethyl cellulose 0.3% Sodium ethylene diamine tetra-acetate l1.9% Sodium sulfate A dispersion was made up containing 0.1 percent ofthis composition, 0.004 percent air born dirt" (obtained from anairfilter) and 0.04 percent of a 1:111 mixture of olive oil, oleic acidand lubricating oil in hard water (258 parts per million as CaCO 250 ml.aliquots of this dispersion were placed in containers of aLaunderometer, together with six 4% inches square swatches of cottonlong cloth. (Cloth to liquor ratio, by weight 1:25). The swatches weresubjected to a 1 hour wash at 38 C. They were then removed, rinsed anddried. This treatment was repeated a further two times. Control testswere carried out in the same conditions using the same detergentcomposition but with the copolymer omitted (Composition B). Thereflectance of the original cotton swatches and of the thrice washedswatches was measured, the variability within the groups of 6 swatchesbeing used to establish 95 percent confidence limits for the results,indicated below as i figures.

Results were:

Unwashed fabric reflectance Washed in Composition A reflectance Washedin Composition B reflectance 94.5 percent t 1.7 units 74 i 1.7 units CHC(R)COOM with a second compound having the formula wherein R is selectedfrom the group consisting of H and CH M is selected from the groupconsisting of H, alkali metal, and ammonium, and n is an integerrepresenting a mean value in the range of from about 5 to about 100, theweight proportion of said first com-. pound to said second compoundbeing in the range of from about 1:1 to 5:1.

2. The copolymers of claim 1 wherein the R of the first compound is Hand the R of the second compound is CH 3. The copolymers of claim 1wherein n is from 20 to 100.

4. The copolymers of claim 1 wherein M is an alkali metal.

5. The copolymers of claim 4 wherein the alkali metal is sodium.

6. The copolymer of claim 1 having a molecular weight of from 30,000 to200,000.

7. The copolymer of claim 1 wherein the first compound is acrylic acidand the second compound is a polyoxyethylene glycol methacrylate whereinthe mean value ofn is 90.

8. The copolymer of claim 1 in which the weight proportion of said firstcompound to said second compound is 2:1.

P0405) UNITED STATES PATENT OFFICE CERTEFKCATE OF CORRECTION Patent No'7 Dated March 1973 Inventor( Frederick Edward Hardy, Peter Robson,Peter Roscoe Hartley Speakman It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 2, line157 delete "proportions" and insert therefor proportionColumn 3,, line 59 delete "monethanolamide" and insert therefore-(solids) Column 3, line 60 delete "monoethanolamine" and inserttherefore monetnanolamide Signed and sealed this 8th day of January197A.

(SEAL) Attest:

EDEMRD MGFLETCHERJR. RENE D. TEGTMEYER Attesting Officer ActingCommissioner of Patents

1. A water-soluble copolymer which results from reacting a firstcompound having the formula CH2 C(R)COOM with a second compound havingthe formula CH2 C(R)COO (C2H4O)nH wherein R is selected from the groupconsisting of H and CH3, M is selected from the group consisting of H,alkali metal, and ammonium, and n is an integer representing a meanvalue in the range of from about 5 to about 100, the weight proportionof said first compound to said second compound being in the range offrom about 1:1 to 5:1.
 2. The copolymers of claim 1 wherein the R of thefirst compound is H and the R of the second compound is CH3.
 3. Thecopolymers of claim 1 wherein n is from 20 to
 100. 4. The copolymers ofclaim 1 wherein M is an alkali metal.
 5. The copolymers of claim 4wherein the alkali metal is sodium.
 6. The copolymer of claim 1 having amolecular weight of from 30,000 to 200,000.
 7. The copolymer of claim 1wherein the first compound is acrylic acid and the second compound is apolyoxyethylene glycol methacrylate wherein the mean value of n is 90.